Effects of reef structural complexity on life history traits of <em>Thalassoma bifascitaum</em>, in Culebra, Puerto Rico.

Abstract

An important consequence of coral mortality is a decrease in reef tridimensional structure (rugosity). A reduction in rugosity reduces shelter for reef inhabitants, increasing the susceptibility of predation and competition. Consequently, to better understand how coral reef communities are shaped in response to reduced structural complexity, it is relevant to investigate the effects of changes in reef structure on the biology and ecology of reef dwelling organisms. This study aims to determine if reef rugosity affects life history traits, such as age, size, and body condition of the tropical reef fish <em>Thalassoma bifasciatum</em>. Two hundred <em>T. bifasciatum</em> individuals were collected from ten quadrant sites that differ in rugosity (quantified as variation in seafloor depth) in Punta Maguey, Culebra, PR. Results demonstrate that there is no significant influence of reef rugosity on <em>T. bifasciatum</em> age structure, growth rate or condition factor when pooling all collected individuals between high and low rugosity sites (p > 0.05). In contrast, significant differences were found when comparing male body length (SL) and body condition (K) from low and high rugosity sites. Specifically, males from high rugosity sites were longer and had higher condition factor than males from low rugosity sites. Further exploration of the interactions between systems and organisms is essential to understand the susceptibility of fish to ecosystem changes and how these changes may affect the sustainability of biological processes in reefs and fish stocks.